Displacement apparatus



Feb. 13, 1945. R. D. DELAMERE DISPLACEMENT APPARATUS Filed May 2, 1942 edema Fat. 1 3. 1945 I tus and more particularly to apparatus which 4 in the accompanying drawing, in which accordance with the variation in the pitch of UNITED. STATES PATENT OFFICE DISPLACEMENTAPPARATUS Rudolf D} Delamere, Toronto, Ontario, Canada 1 Application May 2, 1942, Serial No. 441,511

. '4 Claims. (01. 230-143) therein. The compression ratio of the gas entering and leaving the pockets may be such that the may be driven to serve as a pump or which may pressure of the gas in the small pocket 1 equals be operated to produce mechanical energy to the pressure of the gas in the chamber 8. There serve as a turbine, motor or the like. The object 5 will thus be no flow of gas from the chamber into 01' my present invention is to provide simple apthe small pocket when it is opened whereby only paratus of thischaracter in which the compresthe supply of gas in the small pocket is ejected sion or expansion ratio may be varied. Other by the short pitched portions (i when said pocket objects I have in mind will hereinafter appear. is opened into the chamber. By preventing. the The constructions are hereinafter fully delo backflow of gas'under pressure from the chamber scribed and are illustrated by way of example into the pockets not only is less power required to drive the elements when the apparatus is being Fig. l is a horizontal longitudinal sectioh'o'fthe/ used as a pump but it eliminates flutter or pulsaapparatus; tion from th outflowing gas. Heretofore, in Fig. 2 a horizontal longitudinal sectional detail pumps having elements driven in opposite direcshowing the ribbed elements positioned to obtain tions of rotation it has been found necessary to the maximum ratio of compression or expansion; employ three ribs, formed like a triple thread, on Fig. 3 a cross-section on the line 3-3 in Fig. 1; each element to reduce the noise created by the Fig. 4 an end view of the apparatus showing pulsations. In pumps of the above mentioned the gearing; and 1 p type, what I term, the total geometrical leakage Fig. 5 a detail of a modified form of the apparatus.

In the drawing like numerals of reference indicate corresponding parts in the different figures.

This invention relates to displacement apparaployed. The said. leakage area may be defined a the area of the material removed from a rib to permit the rib of an oppositely rotating elel is a casing which may include a centraland ment to mesh therewith in spite of the difference,

in helical angle'of the top and bottom of a rib.

two end sections 2, 3 and 4. The central section Thus the more ribs'used, the greater the leakage.

2 has two substantially parallel, longitudinally intersecting bores in which are mounted two heli- Moreover, other things being equal this leakage cally ribbed elements 5 so that their ribs 6 will area increases rapidly with an increase in lead. mesh with one another when rotated in opposite By preventing backflow, as hereinbefore dedirections. Each rib on each element comprises a scribed, my pump operates quietly and efilciently comparatively'long pitched portions and a short with only one. or two ribs on each element. If pitched portion 6'. The outside diameter of the the pump is to be operated at high speed which ribbed portions 6 and 6 on each element is connecessitates inherent dynamic balance 'two ribs stant throughout the length'of the element. The are necessary. said portions 6, 6 may be made integral or on The short and long pitched rib portions also separate parts secured together so that the said have another purpose in that steam or other gas portions on each element adjoin one another. under pressure may be directed through the pipe As the elements are rotated, a succession of 8 and chamber 8 into the small pockets to drive pockets 1", l are formed which vary in size in 40 the elements 5. The steam or other compressed gas trapped in the small pockets will travel lonthe rib 6. The large sized pockets 1 are formed gitudinally as the short pitched portions of the by the peripheral spaces between adjacent ribs ribs 6 are rotated until it is brought into contact on the long pitched portion 6 and the wall of the with the long pitched portions of the ribs when bore in which the element is rotated, and the it will expand into the succeeding large pockets small sized pockets I are similarly formed by the thus providing additional energy without addishort pitched portions 6''. The small pockets comtional steam. The expanded gas then escapes municate with a chamber 8 in the end section through the openings 9. 3 of the casing. Said chamber has an outlet 8. The opposite ends of the elements are provided The large pockets communicate with openings 9 with spindles which are ioumalled in the end in the end section 4. Thus gas trapped in a large sections 3 and 4. These spindles are of suflicient pocket I is moved longitudinally by the long length to permit" relative axial movement of the pitched portion 6* into contact with the short elements 5 and the casing l whereby the compitched portion 6 whereby the pocket is reduced pression or expansion ratio between the pockets to the small'pocket 1'? and the gas is compressed 'F- and 1 may be varied. The spindles may be area increases directly as the number of ribs emconnected, at one end of the casing, by a bar l and, at the other end of the casing. by a disk II and flanged wheel I2 to receive the disk. Pinions l9 suitably carried by the spindles are meshed with one another to rotate the elements in opposite directions of rotation. One of the spindles carries a long pinion I3 which meshes with a gear I on a shaft I! which is suitably journalled in a housing I 6 carried by the end section 4. The shaft l carries one or more pulleys ll whereby .the shaft may be driven to drive the elements or the latter may be driven to drive the pulleys.

One or more springs l8, disposed on studs or the like threaded into the end section 3, may be employed to urge the elements 5 to the position shown in Fig. 1 in which only about of the small pockets is effective and thus the compression ratio is about 1.25 to 1, i. e., about 80% out-ofl. The spring l8 bears against the bar I0 to urge it against the nut 2| threaded on the stud 20. The nut thus forms a stop to limit the axial movement of the elements 5 and initially control the point of communication between the pockets 1* and the bores in the casing as shown in Fig. 1. It is obvious that the point of communication may be varied to vary the compression ratio of the gas by adjusting the nut 2i on its stud 20. It the apparatus is being used as a Dump, the pressure in the chamber 8 gradually increases to correspondingly shift the elements relative to their bores against the compression of the spring I8 whereby the small pockets I are correspondingly closed to increase the compression ratio until it reaches its maximum as shown in Fig. 2. In the drawin the maximum ratio is 4 to l, i. e., 25% cut-oi! since the long pitch 6 of the ribs 5 is four times the length of the short pitch 6. If the short pitched portions of the elements are entirely withof the elements being of greater cross sectional area than that of the bores; means for admitting or exhausting gas into or from the last mendrawn from the bores in the casing only the large pockets are closed and a one to one compression ratio would be obtained, i. e., 100% cut-off. If the apparatus is being used as a turbine in whichsteam or other gas under pressure is admitted through the pipe 8 into the chamber 8, the elements would be shifted to obtain the maximum expansion ratio between the small and large pockets immediately suflicient pressure is' built up in the chamber to overcome the pressure of the spring or springs l8. As the elements are axially moved to cover or to uncover the small pockets 1', the teeth of the long pinion ll slide across the intermeshing teeth of the-gear ll.

tioned end section; means for exhausting or admitting gas from or into the other end section, the gas being thus brought directly into communication with the small or largepockets and with the ends of the ribbed elements, the elements being axially movable in the bores in a direction to correspond to a difference in pressure between the end sections, the extent of movement of the short pitched portions into the bores varying the length of the small pockets to correspondingly vary the compression or expansion ratio of said small and large pockets; and spring means opposing the axial movement of the elements by pressure against the ends of the elements adjacent the short pitched portions thereof to proportion the extent of movement of said short pitched portions into the bores in accordance with the pressure against the said ends.

2. A gas pump or motor constructed in accordance with claim 1 in which a stop is provided to limit the axial movement of the elements imparted thereto by the spring means so that a predetermined length of the short pitched portions of the elements may be initially positioned in the bores to obtain an initial compression or expan- 1 ,sion ratio.

3. A gas pump or motor comprising a casing having a central and two end sections, the central section having two bores intersecting one another; two axially movable helically ribbed elements meshed with one another and rotatable in opposite directions in said bores to form gas trapping pockets between the ribs and the walls of the bores, the ribs on the elements having comparatively long and short pitched portions to form large and small pockets, the end section of the 4b casing adjacent the short pitched Portions of the elements being of greater cross sectional area than that of the bores; means for admitting or exhausting gas into or from the last mentioned end section; means for exhausting or admitting gas from or into the other end section, the gas being thus brought directly into communication with the small or large pockets and with the ends of the ribbed elements, the elements being axially It will be distinctly understood that various modifications may be made without departing from the spirit of the invention. For instance, the intermeshing elements 5 may be mounted in longitudinally intersecting bores formed in nonrotary sleeves I which are suitably guided for axial movement relative to the casing I and to the elements 5. Thus by manually or automati cally moving the sleeves axially relative to the elements, the compression or expansion ratio between the large and small pockets will be varied.

What I claim as my invention is:

1. A gas pump or motor comprising a casing having a central and two end sections, thecentral section having two bores intersecting one' of the casing adjacent the short pitched portions movable in the bores in a direction to correspond to a difierence in pressure between the end sections, the extent of movement of the short pitched portions into the bores varying the length of the small pockets to correspondingly vary the compression -or expansion ratio of said small and large pockets; spring means opposing the axial movement of the elements by pressure against the ends of the elements adjacent the short pitched portions thereof to proportion the extent of movement of said short pitched portions into the bores in accordance with the pressure against the said I ends; and an adjustable stop for limiting the axial movement of the elements imparted thereto by the pring means so that a variable predetermined length of the short pitched portions of the elements may be initially positioned in the bores to obitfin a variable initial compression or expansion ra o.

4. A. gas pump or motor comprising a casing having a central and two end sections, the central section having two bores intersecting one another; two helically ribbed elements meshed with one another and rotatable in opposite directions in said bores to form gas trapping pockets between the ribs and the walls of the bores,

the ribs on the element having comparatively asoasse long and short pitched portions to form large and small pockets, the end section of the casing. adjacent the short pitched portions of theelements being of greater cross sectional area than that of the bores, the elements and bores being axially movable relative to one another: means for admitting or exhausting gas into or from the last mentioned end section: means for exhausting or admitting gas from or into the other end section, the gas being thus brought directly into communication with the small or large pockets and with the'ends of the ribbed elements, the elements and bores being axially movable relative to one another in a direction to correspond to a diiferenoe in pressure between the end sections. the extent of relative movement or the elements and bores varying the length of the small pockets in the bores to correspondingly vary the compression or expansion ratio at said small. and largepockets: and spring means opposing the relative movement of said elements and bores by pressure against the movable part of said elements and bores to resist an increase in the length of the small pockets to proportion the length of said small pockets in accordance with the aforesaid pressure against the movable part oi said elements and bores.

, RUDOLF D. DELAMERE. 

